Okay so you just gotta break it down, so first you do 420 divided by 15. Which equals 28. so now you find the shape that equals 28. now with the shapes completely ignore whats inside them cause that will confuse you. on top of shape D there is a 10 and a 5. 10+5=15 then on the side of shape d there is a 28 on the side so you do 28 times 15. which equals 420. so D would be your answer.